Commit a25de534 authored by Anton Arapov's avatar Anton Arapov Committed by David S. Miller
Browse files

[INET]: Justification for local port range robustness. 

  There is a justifying patch for Stephen's patches. Stephen's patches
disallows using a port range of one single port and brakes the meaning
of the 'remaining' variable, in some places it has different meaning.
My patch gives back the sense of 'remaining' variable. It should mean
how many ports are remaining and nothing else. Also my patch allows
using a single port.

  I sure we must be able to use mentioned port range, this does not
restricted by documentation and does not brake current behavior.

usefull links:
Patches posted by Stephen Hemminger
  http://marc.info/?l=linux-netdev&m=119206106218187&w=2
  http://marc.info/?l=linux-netdev&m=119206109918235&w=2

Andrew Morton's comment
  http://marc.info/?l=linux-kernel&m=119248225007737&w=2



1. Allows using a port range of one single port.
2. Gives back sense of 'remaining' variable.

Signed-off-by: default avatarAnton Arapov <aarapov@redhat.com>
Acked-by: default avatarStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent be702d5e

drivers/infiniband/core/cma.c

+3 −2
Original line number Diff line number Diff line
@@ -2797,11 +2797,12 @@ static void cma_remove_one(struct ib_device *device) 


static int cma_init(void)

{

	int ret, low, high;

	int ret, low, high, remaining;



	get_random_bytes(&next_port, sizeof next_port);

	inet_get_local_port_range(&low, &high);

	next_port = ((unsigned int) next_port % (high - low)) + low;

	remaining = (high - low) + 1;

	next_port = ((unsigned int) next_port % remaining) + low;



	cma_wq = create_singlethread_workqueue("rdma_cm");

	if (!cma_wq)

net/ipv4/inet_connection_sock.c

+1 −1
Original line number Diff line number Diff line
@@ -93,7 +93,7 @@ int inet_csk_get_port(struct inet_hashinfo *hashinfo, 
		int remaining, rover, low, high;



		inet_get_local_port_range(&low, &high);

		remaining = high - low;

		remaining = (high - low) + 1;

		rover = net_random() % remaining + low;



		do {

net/ipv4/inet_hashtables.c

+1 −1
Original line number Diff line number Diff line
@@ -286,7 +286,7 @@ int inet_hash_connect(struct inet_timewait_death_row *death_row, 
		struct inet_timewait_sock *tw = NULL;



		inet_get_local_port_range(&low, &high);

		remaining = high - low;

		remaining = (high - low) + 1;



		local_bh_disable();

		for (i = 1; i <= remaining; i++) {

net/ipv4/sysctl_net_ipv4.c

+2 −2
Original line number Diff line number Diff line
@@ -122,7 +122,7 @@ static int ipv4_local_port_range(ctl_table *table, int write, struct file *filp, 
	ret = proc_dointvec_minmax(&tmp, write, filp, buffer, lenp, ppos);



	if (write && ret == 0) {

		if (range[1] <= range[0])

		if (range[1] < range[0])

			ret = -EINVAL;

		else

			set_local_port_range(range);
@@ -150,7 +150,7 @@ static int ipv4_sysctl_local_port_range(ctl_table *table, int __user *name, 


	ret = sysctl_intvec(&tmp, name, nlen, oldval, oldlenp, newval, newlen);

	if (ret == 0 && newval && newlen) {

		if (range[1] <= range[0])

		if (range[1] < range[0])

			ret = -EINVAL;

		else

			set_local_port_range(range);

net/ipv4/udp.c

+3 −2
Original line number Diff line number Diff line
@@ -147,13 +147,14 @@ int __udp_lib_get_port(struct sock *sk, unsigned short snum, 
	write_lock_bh(&udp_hash_lock);



	if (!snum) {

		int i, low, high;

		int i, low, high, remaining;

		unsigned rover, best, best_size_so_far;



		inet_get_local_port_range(&low, &high);

		remaining = (high - low) + 1;



		best_size_so_far = UINT_MAX;

		best = rover = net_random() % (high - low) + low;

		best = rover = net_random() % remaining + low;



		/* 1st pass: look for empty (or shortest) hash chain */

		for (i = 0; i < UDP_HTABLE_SIZE; i++) {

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